"Spartacus: War of the Damned" Spartacus' (Liam McIntyre) plans are threatened by a potential betrayal in this new episode. 9 p.m. Starz

"Portlandia" Electricity is shut off for the entire city as a result of unpaid bills at the mayor's office in the season finale of the quirky comedy. Carrie Brownstein and Fred Armisen star. 10 p.m. IFC

"Save the Titanic With Bob Ballard: Revealed" In the first of two new specials the famed oceanographer works to protect the final resting place of his greatest discovery. Then Ballard reveals new details about his search for the ill-fated vessel in "Titanic: Ballard's Secret Mission: Revealed" 8 and 9 p.m. Nat Geo.